Hypoxemia and critical illnesses such as sepsis and disseminated intravascular coagulopathy (DIC) are possible causes of massive microbleeds in the brain parenchyma [1]. We report a patient with human immunodeficiency virus (HIV) showing extensive cerebral microbleeds. A 59-year-old male patient presented with generalized tonic-clonic seizures. After admission, he was diagnosed with HIV infection while evaluating for pneumonia. Ten days after antiretroviral therapy (ART), DIC occurred as a result of pneumonia progression, compatible with immune reconstitution inflammatory syndrome (IRIS). Blood analysis showed elevated D-dimer levels (1,750 ng/mL), prolonged prothrombin time (16.1 seconds), and low platelet count (63×10³/μL). He was stuporous with normal brainstem signs of brainstem injury. While the patient’s brain computed tomography images were unremarkable (Fig. 1A), susceptibility-weighted images demonstrated innumerable hypointense foci in the cerebrum and cerebellum suggestive of microbleeds (Fig. 1B). Multifocal hyperintense lesions were also observed in the fluid-attenuated inversion recovery images, which could induce a symptomatic seizure (Fig. 1C). Meanwhile, the cerebrospinal fluid examination was within the normal range. Anti-epileptic drugs were administered, and the patient’s mental status improved from stuporous to alert.